Applications of International Terrestrial Reference Frame in Geometric and Dynamic Geodesy

Abstract

Inthiswork,twocriticalgeodeticissuesinEgyptwerediscussed. Firstly,thedynamicnatureofInternationalTerrestrialReference Frame (ITRF) as a geodetic datum, while the main Global Posi- tioning System (GPS) network in Egypt is tied to a static datum is considered a critical geodetic issue. Tying any derived ITRF coordinates to the Egyptian network cannot be directly applied due to the effect of the tectonic plate motion, in addition to the datum definition change from one ITRF realization to another. The simplest solution is neglecting the effect of the datum def- inition change and using a Plate Motion Model (PMM) for the backwardpropagationofcoordinatesuntilthespecifiedepochof thestaticdatum.However,themostopportunesolutionisapply- ingthe14-parameterdatumtransformation.Inthisstudy,anew set of 14 parameters was derived to describe thetransformation processoftheAfricanplateinabetterway.Assessmentthequal- ityofbothsolutionsbasedonrecentGlobalNavigationSatellite System (GNSS) observations, for 4 stations from the Egyptian network, was presented. In addition, 5 different PMM(s) were usedtoassessthecompatibilityoftherecentPMM(s)withthe